Chapter 4: Tissue Level Organization Flashcards
Name the 4 different types of human tissue.
Epithelial Tissue
Connective Tissue
Muscle Tissue
Nervous Tissue
Describe the characteristics and functions of epithelial tissue. Examples of structures and locations.
Lines every body surface and all body cavities.
Constitutes most glands
One or more layers of closely packed cells form a barrier
Composed of cells bound by cell junctions
3 surfaces: Apical surface (top surface) Intercellular junctions (lateral surface) Basal surface (fixed, bottom surface) - bound to basement membrane
Lacks blood vessels so nutrients are obtained directly across apical surface or by diffusion across basal surface.
Some is richly innervated.
High regeneration capacity - continual replacement
Functions: Protection (skin) Regulation of materials in/out of organ tissue Produce secretions The Senses
Describe the characteristics and functions of connective tissue. Examples of structures and locations.
Binds body structures together.
Most diverse and abundant tissue.
Examples: cartilage, bone, blood, tendons/ligaments, fat
Function:
- Support (bones)
- Protect (skin, bones),
- Bind structures (tendons, ligaments)
- Storage (fat)
- Transport (blood)
3 Basic components:
- cells
- protein fibers
- ground substance
CELL TYPES
Connective tissue contains fibroblasts which regenerate tissue; Fat - adipocyte; Cartilage - chondrocytes; Bone - osteocytes; white blood cells etc for phagocytosis
PROTEIN FIBERS
throughout the tissue; strengthen and support; collagen, elastic and reticular fibers
Loose and Dense types
Loose - cushions organs (adipose)
Dense - everything else (tendons, skin, stomach)
Describe the characteristics and functions of muscle tissue. Examples of structures and locations.
Respond to stimulation from the nervous system
Voluntary and Involuntary movements
3 types
Skeletal (striated) - voluntary
Smooth (non-striated) - Involuntary i.e. stomach, intestines
Cardiac (striated) - Involuntary - heart
Describe the characteristics and functions of nervous tissue. Examples of structures and locations.
Consists of neurons and glial cells
Functions:
Detect stimuli, process info fast, transmit impulse from one region of the body to another
processingm storage, and retrieval; internal communication.
Discuss tissue damage, repair, and death
Metaplasia: Tissue starts as one tissue and becomes another.
Hypertrophy: CELL gets bigger
Hyperplasia: AMOUNT of cells increases
Regeneration: Regrowth
Neoplasia: Out of control growth - cancer
Fibrosis: scar tissue
Atrophy: Shrinking of tissue either by cell size or number.
Define tissues.
Group of similar cells and extracellular products that carry out a common function.
Basic functions and types of epithelial tissue.
Simple: One layer; Absorption/secretion
Stratified: Many layers; Protection/secretion
Shapes: Squamous, cuboidal, columnar, transitional.
Name the 4 types of cell junctions.
- tight junctions: “gate keepers” between external and internal environment
- adhering junctions: deep to tight junctions
- desmosomes: “snap” little piece connecting cells
- gap junctions: “tunnel” that connects one cell to another so items can pass through i.e. glucose (like the can and string example - allows communication between cells)
Endocrine Glands
Secrete directly into the blood stream. i.e. hormones
Exocrine Glands
Maintain contact with surface via a duct. Duct secretes materials on the skin surface or lining of internal passageway.
simple or compound glands; tubular (tubes) or acinar (sacs) or tubuloacinar (both) ducts
Describe the differences between:
Merocrine glands
Holocrine glands
Apocrine glands
Merocrine glands: package secretions in vesicles and release by exocytosis i.e. salivary glands, gastric glands,
Holocrine glands: secretion produced by destruction of cell i.e. sebaceous glands
Apocrine glands: “decapitation,” top of cell squeezes off i.e. sweat glands/mammary glands
Cartilage
3 types
Hyaline - ends of bones (i.e. also nose, trachea)
Fibrocartilage - more firm, not as flexible (i.e. meniscus, vertebral discs)
Elastic - bend it and it goes back to it’s shape (i.e. external ear)
Bone
3 layers
Periostium - outer sheath surrounds bone but not on the ends
Compact - structure is close together, strong, small holes
Spongy - bigger holes, toward middle of the bone
osteocytes make and maintain regrowth of bone
Fluid Connective Tissue
Blood
(erythrocytes) red blood cells - transport O2 and CO2
(leukocytes) white blood cells - antibodies
platelets - clotting factor